Frequent intermittent timeouts in macOS WPT tests

[jdm]

6 unexpected results that are NOT known-intermittents:
  â–¶ TIMEOUT [expected PASS] /css/css-flexbox/flexbox_align-items-flexend.html
  │ 
  │ _RegisterApplication(), FAILED TO establish the default connection to the WindowServer, _CGSDefaultConnection() is NULL.
  │ 
  │ 
  │ 
  │ Shutting down the Constellation after generating an output file or exit flag specified
  â”” 36 threads are still running after shutdown (bad).


  â–¶ TIMEOUT [expected PASS] /css/css-ui/outline-007.html
  │ 
  │ _RegisterApplication(), FAILED TO establish the default connection to the WindowServer, _CGSDefaultConnection() is NULL.
  │ 
  │ 
  │ 
  │ Shutting down the Constellation after generating an output file or exit flag specified
  │ 44 threads are still running after shutdown (bad).
  │ _RegisterApplication(), FAILED TO establish the default connection to the WindowServer, _CGSDefaultConnection() is NULL.
  │ 
  │ 
  │ 
  │ Shutting down the Constellation after generating an output file or exit flag specified
  â”” 19 threads are still running after shutdown (bad).


  â–¶ TIMEOUT [expected FAIL] /css/css-ui/box-sizing-012.html
  │ 
  │ _RegisterApplication(), FAILED TO establish the default connection to the WindowServer, _CGSDefaultConnection() is NULL.
  │ 
  │ 
  │ 
  │ Shutting down the Constellation after generating an output file or exit flag specified
  â”” 19 threads are still running after shutdown (bad).


  â–¶ TIMEOUT [expected FAIL] /css/css-ui/box-sizing-024.html
  │ 
  │ _RegisterApplication(), FAILED TO establish the default connection to the WindowServer, _CGSDefaultConnection() is NULL.
  │ 
  │ 
  │ 
  │ Shutting down the Constellation after generating an output file or exit flag specified
  â”” 40 threads are still running after shutdown (bad).


  â–¶ TIMEOUT [expected FAIL] /css/css-ui/box-sizing-008.html
  │ 
  │ _RegisterApplication(), FAILED TO establish the default connection to the WindowServer, _CGSDefaultConnection() is NULL.
  │ 
  │ 
  │ 
  │ Shutting down the Constellation after generating an output file or exit flag specified
  â”” 19 threads are still running after shutdown (bad).


  â–¶ TIMEOUT [expected PASS] /css/css-flexbox/ttwf-reftest-flex-inline.html
  │ 
  │ _RegisterApplication(), FAILED TO establish the default connection to the WindowServer, _CGSDefaultConnection() is NULL.
  │ 
  │ 
  │ 
  │ Shutting down the Constellation after generating an output file or exit flag specified
  â”” 19 threads are still running after shutdown (bad).

The _RegisterApplication() warnings are unrelated to the timeouts, which often happen independently.

[jdm]

The warnings about threads are also independent of the fact that the timeout occurs.

[SimonSapin]

Possibly the same root cause as #24735. But it’s apparently become much worse lately, I don’t know why.

This is just now:

$ ./mach salt 'mac?' cmd.run '/opt/local/bin/zombicide sigterm'
mac2:
    pid 21640 /Users/worker/tasks/task_1578509591/repo/target/release/servo, 57.0% CPU, running for 5 days, 2:28:39
    pid 87498 /Users/worker/tasks/task_1578497747/repo/target/release/servo, 57.0% CPU, running for 5 days, 6:30:13
    Killed 2 processes
mac7:
    pid 37486 /Users/worker/tasks/task_1578929966/repo/target/release/servo, 36.6% CPU, running for 6:25:37
    pid 37492 /Users/worker/tasks/task_1578929966/repo/target/release/servo, 36.6% CPU, running for 6:25:36
    pid 39450 /Users/worker/tasks/task_1578810703/repo/target/release/servo, 37.0% CPU, running for 1 day, 15:33:43
    pid 51005 /Users/worker/tasks/task_1578933855/repo/target/release/servo, 36.8% CPU, running for 3:55:31
    Killed 4 processes
mac3:
    pid 39244 /Users/worker/tasks/task_1578561700/repo/target/release/servo, 37.0% CPU, running for 4 days, 12:43:45
    pid 50099 /Users/worker/tasks/task_1578671036/repo/target/release/servo, 37.0% CPU, running for 3 days, 6:19:57
    pid 68798 /Users/worker/tasks/task_1578928269/repo/target/release/servo, 37.2% CPU, running for 7:02:18
    pid 72659 /Users/worker/tasks/task_1578749583/repo/target/release/servo, 37.1% CPU, running for 2 days, 8:30:48
    pid 76809 /Users/worker/tasks/task_1578517251/repo/target/release/servo, 37.0% CPU, running for 5 days, 1:05:08
    pid 95390 /Users/worker/tasks/task_1578595605/repo/target/release/servo, 37.1% CPU, running for 4 days, 3:17:35
    Killed 6 processes
mac1:
    pid 6701 /Users/worker/tasks/task_1578951399/repo/target/release/servo, 35.8% CPU, running for 0:34:39
    pid 22486 /Users/worker/tasks/task_1578527749/repo/target/release/servo, 35.7% CPU, running for 4 days, 22:07:52
    pid 22625 /Users/worker/tasks/task_1578494776/repo/target/release/servo, 35.9% CPU, running for 5 days, 7:18:50
    pid 29646 /Users/worker/tasks/task_1578529937/repo/target/release/servo, 36.0% CPU, running for 4 days, 21:30:19
    pid 58753 /Users/worker/tasks/task_1578917430/repo/target/release/servo, 35.9% CPU, running for 10:01:03
    pid 92858 /Users/worker/tasks/task_1578592647/repo/target/release/servo, 35.9% CPU, running for 4 days, 4:03:55
    pid 97097 /Users/worker/tasks/task_1578707013/repo/target/release/servo, 35.7% CPU, running for 2 days, 20:19:01
    Killed 7 processes
mac4:
    pid 26445 /Users/worker/tasks/task_1578481079/repo/target/release/servo, 20.3% CPU, running for 5 days, 11:03:59
    pid 32971 /Users/worker/tasks/task_1578925225/repo/target/release/servo, 20.3% CPU, running for 7:51:32
    pid 56630 /Users/worker/tasks/task_1578542368/repo/target/release/servo, 20.1% CPU, running for 4 days, 18:03:38
    pid 63359 /Users/worker/tasks/task_1578674507/repo/target/release/servo, 20.2% CPU, running for 3 days, 5:10:05
    pid 65763 /Users/worker/tasks/task_1578929822/repo/target/release/servo, 20.2% CPU, running for 6:28:16
    pid 65768 /Users/worker/tasks/task_1578929822/repo/target/release/servo, 20.4% CPU, running for 6:28:14
    pid 73013 /Users/worker/tasks/task_1578931974/repo/target/release/servo, 20.2% CPU, running for 5:48:23
    pid 73018 /Users/worker/tasks/task_1578931974/repo/target/release/servo, 20.2% CPU, running for 5:48:22
    pid 74517 /Users/worker/tasks/task_1578679125/repo/target/release/servo, 20.1% CPU, running for 3 days, 3:07:14
    pid 84622 /Users/worker/tasks/task_1578505152/repo/target/release/servo, 20.2% CPU, running for 5 days, 4:13:08
    pid 86261 /Users/worker/tasks/task_1578686474/repo/target/release/servo, 19.3% CPU, running for 3 days, 2:00:41
    pid 95499 /Users/worker/tasks/task_1578509407/repo/target/release/servo, 19.4% CPU, running for 5 days, 3:12:26
    Killed 12 processes
mac9:
    pid 5801 /Users/worker/tasks/task_1578536577/repo/target/release/servo, 19.8% CPU, running for 4 days, 19:41:58
    pid 15454 /Users/worker/tasks/task_1578685796/repo/target/release/servo, 19.7% CPU, running for 3 days, 2:13:10
    pid 24328 /Users/worker/tasks/task_1578917685/repo/target/release/servo, 19.7% CPU, running for 9:47:05
    pid 24333 /Users/worker/tasks/task_1578917685/repo/target/release/servo, 19.8% CPU, running for 9:47:04
    pid 28582 /Users/worker/tasks/task_1578691288/repo/target/release/servo, 19.8% CPU, running for 3 days, 0:44:15
    pid 50433 /Users/worker/tasks/task_1578571390/repo/target/release/servo, 19.2% CPU, running for 4 days, 10:01:37
    pid 50473 /Users/worker/tasks/task_1578714883/repo/target/release/servo, 19.2% CPU, running for 2 days, 18:10:46
    pid 61396 /Users/worker/tasks/task_1578750706/repo/target/release/servo, 19.2% CPU, running for 2 days, 6:53:17
    pid 75826 /Users/worker/tasks/task_1578677342/repo/target/release/servo, 19.2% CPU, running for 3 days, 4:34:02
    pid 79611 /Users/worker/tasks/task_1578806456/repo/target/release/servo, 19.2% CPU, running for 1 day, 16:40:40
    pid 91284 /Users/worker/tasks/task_1578603738/repo/target/release/servo, 19.2% CPU, running for 4 days, 0:41:28
    pid 95593 /Users/worker/tasks/task_1578940247/repo/target/release/servo, 19.3% CPU, running for 3:33:40
    pid 95598 /Users/worker/tasks/task_1578940247/repo/target/release/servo, 19.2% CPU, running for 3:33:39
    Killed 13 processes
mac5:
    pid 8333 /Users/worker/tasks/task_1578535956/repo/target/release/servo, 22.2% CPU, running for 4 days, 19:50:40
    pid 11767 /Users/worker/tasks/task_1578504728/repo/target/release/servo, 22.2% CPU, running for 5 days, 4:31:29
    pid 13409 /Users/worker/tasks/task_1578829270/repo/target/release/servo, 22.1% CPU, running for 1 day, 10:12:27
    pid 60904 /Users/worker/tasks/task_1578518302/repo/target/release/servo, 22.2% CPU, running for 4 days, 23:53:18
    pid 67626 /Users/worker/tasks/task_1578924929/repo/target/release/servo, 22.2% CPU, running for 7:46:40
    pid 67632 /Users/worker/tasks/task_1578924929/repo/target/release/servo, 22.2% CPU, running for 7:46:38
    pid 76020 /Users/worker/tasks/task_1578930513/repo/target/release/servo, 22.6% CPU, running for 6:23:22
    pid 79232 /Users/worker/tasks/task_1578486299/repo/target/release/servo, 17.8% CPU, running for 5 days, 9:40:07
    pid 98534 /Users/worker/tasks/task_1578580200/repo/target/release/servo, 22.2% CPU, running for 4 days, 7:18:18
    Killed 9 processes
mac6:
    pid 393 /Users/worker/tasks/task_1578945625/repo/target/release/servo, 42.2% CPU, running for 0:39:19
    pid 33557 /Users/worker/tasks/task_1578498913/repo/target/release/servo, 41.3% CPU, running for 5 days, 6:09:11
    pid 93617 /Users/worker/tasks/task_1578528491/repo/target/release/servo, 41.4% CPU, running for 4 days, 21:56:30
    pid 93725 /Users/worker/tasks/task_1578944667/repo/target/release/servo, 41.3% CPU, running for 2:27:22
    Killed 4 processes
mac8:
    pid 9480 /Users/worker/tasks/task_1578555499/repo/target/release/servo, 23.4% CPU, running for 4 days, 14:23:04
    pid 31670 /Users/worker/tasks/task_1578810776/repo/target/release/servo, 23.4% CPU, running for 1 day, 15:25:33
    pid 73648 /Users/worker/tasks/task_1578945259/repo/target/release/servo, 23.4% CPU, running for 2:07:00
    pid 73653 /Users/worker/tasks/task_1578945259/repo/target/release/servo, 23.4% CPU, running for 2:06:58
    pid 75292 /Users/worker/tasks/task_1578658403/repo/target/release/servo, 23.5% CPU, running for 3 days, 9:48:26
    pid 84048 /Users/worker/tasks/task_1578504064/repo/target/release/servo, 23.4% CPU, running for 5 days, 4:43:20
    pid 92618 /Users/worker/tasks/task_1578546541/repo/target/release/servo, 23.4% CPU, running for 4 days, 16:27:42
    Killed 7 processes

[jdm]

I'm pretty sure I've seen timeout results from test runs that started right after I killed all zombie processes, so I'm not even convinced there's a direct cause and effect with them.